Computer Controlled Capacitor Reformer

[Zenith6S321]

I opened this thread here because a couple of the threads in this section discussed capacitor reforming. Please move this to the correct section. The thread: http://www.videokarma.org/showthread...=256816&page=3 talked about plotting cap reforming data. I put together a computer controlled capacitor reformer that captures current and voltage data while limiting the current and voltage to user specified values. The intention is to make a cap reformer that, once started, can complete the process with no user monitoring. Attached is a schematic of the current state of my project. It plugs into a PC using a USB cable and is powered by 120VAC. I uses an Arduino Uno processor (about 2" by 3") and a Seeed Motor Controller to provide two 2A 16V pulse width modulated drives from the motor contrller connected to two 12.6V to 120V step up transformers. All of this is from Radio Shack. The two 120V output windings are connected in series and drive a voltage quadrupler. Current and voltage sensing resistors are used to monitor the capacitor reforming process using two of the Arduino Uno analog inputs. The system is able to generate voltages up to almost 900VDC under program control. The above referenced thead has current, voltage, computed resistance, and computed power plots of four capacitors being reformed. Attached is a schematic of the current state of the hardware, as requested in the other thread. I started this thread so as not to hijack the other thread. I have some more modifications to add controls to make the unit not need the PC to set the reforming parameters.

[Geist]

Hi All;
This looks Great.. I am impressed, not only with its simplicity, but, its elegence.. THANK YOU for Posting this..
THANK YOU Marty

[Zenith6S321]

Thanks for the kind words. I had been looking for a project that I could use to learn about the Arduino, and when I saw the motor controller it occured to me that it might survive the back EMF of a transformer to let me make a computer controlled high voltage supply.
The two 630TS caps that I have gotten to reform so far show a lot of dielectric absorption. This Wiki explains it: http://en.wikipedia.org/wiki/Dielectric_absorption
Since those two caps are in the power supply, they could probably be used if I wanted to live dangerously. I will definitely replace the ones not in the power supply circuits, especially the ones in the deflection circuits. The last thing I would want to do is destroy irreplaceable parts to save the price of a few capacitors.

[DaveWM]

interesting reading. I would be nice to know how those old caps performed when new.

[Zenith6S321]

I just spotted a mistake in the schematic, sigh. Attached is the corrected schematic. C7 should be across the small ADC1 voltage, not the full cap reforming voltage.

[Bill R]

C7 appears in the same place on both schematics. Or I don't see a difference.

[Geist]

Hi All;
R6 has changed position..
THANK YOU Marty

[Bill R]

K. I see. Thanks.

[Zenith6S321]

Attached is an updated schematic (changed C7 from 220uF to 4.7uF). The Arduino code for the hardware is also attached. It is used by opening compiling and running the Arduino code in the IDE and them opening the Tools/Serial Monitor and answering the questions. The reforming progress is printed to the serial monitor window.

Dave